The present invention relates to means for selectively positioning needles in a circular knitting machine, and more particularly to needle raising cams and associated clearing cams.
Needle positioning cams of various types are well known in the art for manipulating needles to produce various knitting functions. As these needle positioning cams must be introduced into the normal path of the control butts of needles or jacks in order to effect needle manipulation, special motions must be provided for introducing the cams or additional cam mechanisms with complicated linkages utilized or special control butt patterns provided so that the cam can be inserted in a space where there are no butts.
By the present invention, a simple radially insertable needle positioning cam is used with a pivoted needle raising cam in advance of the positioning cam to clear the control butts during insertion of the needle positioning cam and to raise the control butts for engagement with the positioning cam when it is in its inserted position, and this is accomplished with a simple and inexpensive mechanism without special patterns of needle or jack butts. Furthermore, the raising cam can be positioned at a relatively low incline for preliminary raising of needles to the positioning cam so that high speed cylinder rotation can be accommodated.